Type: Quaternary amine
Receptors: Nicotinic (ionotropic), Muscarinic (metabotropic)
Region-specific functions:

• Basal forebrain (nucleus basalis): Projects to cortex → attention, learning

• Hippocampus: Memory encoding

• Brainstem (pedunculopontine nucleus): Arousal, REM sleep regulation

• Motor cortex → spinal cord → muscles: Controls voluntary movement

• Loss of cholinergic neurons → Alzheimer’s disease